Recent comments in /f/askscience

WHOmagoo t1_j9hbm0q wrote

Reply to Does high altitude supersonic flight push air into space? by CertainlyUnreliable

There is no formal definition for the end of the atmosphere and the beginning of space, but an altitude can be arbitrarily chosen. A common choice is the Kármán Line which is an altitude of 100km. But 101km above would still have low amounts of atmosphere in it and I wouldn't consider it in space if it stays near the earth.

The link states that the Kármán Line is well above the altitude that traditional aircraft are able to fly at.

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thenewmadmax t1_j9h9m6u wrote

Reply to Are some people immune to HIV? by Lass_OM

Generally speaking, yes it's quite possible that some people are immune to HIV, the trouble is that because they never get infected, people don't really know they contracted it, and then fought it off.

Transmission rates are also not 100%, especially if you're a 'top' the chances of not getting it go down even further, so it's very hard to test against a control. Were somebody to become aware of a possible infection the standard operating procedure would be to start an anti viral regiment as soon as possible to prevent the infection from taking hold, which further reduces the chances to study this possibility.

There have been tidbits of useful data though, such as the Berlin patient which has been mentioned by others.

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Stevej38857 t1_j9h8war wrote

Reply to when a limb gets amputated, how do they stop the flow of blood? by EnchantedCatto

Anytime the subject of amputation comes up, I always think about the many men who lost limbs during the Civil War. I've always wondered if most of it was really necessary or if the surgeons were overwhelmed and made quick decisions. I know there was a problem with lead poisoning. But didn’t some survive torso wounds?

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